How to export the bearing of an event along a trajectory?

I have a continuous topo collected at a very high logging rate that I use to calculate a trajectory. During the collection I have events logged to the Trimble GNSS unit when a picture is taken. I process the baselines for the continuous topo collection to a local base to create the trajectory and the locations of the events, which are interpolated along the trajectory. I can export the X,Y,Z coordinates for the events, but I'd also like the bearing (azimuth) of the trajectory at each event, so I can calculate an offset to a camera that isn't directly under the antenna. Does anyone know how to extract a bearing from a trajectory in TBC?